urban areas often dominate the nation—in population growth and in economic activity. Political upheavals and employment opportunities in the cities, teamed with the declining capacity of agriculture to offer profitable employment, have been far more important influences on migration than changes in fertility or mortality rates. What are the political effects of migration? First of all, by definition, all migration involves a political act. The U.S. census considers that a migrant is any person who has moved from one county to another, but an individual who moves within the county is simply considered a "mover." In India, the census defines a migrant as any person who has moved from one district to another, though Zachariah (56) in his study of internal migration in India uses the state as the unit. Other scholars speak of rural migrants to urban areas, though the migration may be within a single district or within a single county. All these usages, however, have a common requirement that migration involves a move from one political unit to another. Therefore, there are political implications to the movements of people regardless of why they move. The distinction between migrant and mover emphasizes at least two important repercussions. For one thing, it calls attention to the fact that the political units which are affected by the migration are often able to take steps to encourage or discourage the migrants, or may treat migrants differently from local inhabitants. For example, there may be residential requirements for voting, or, as in the United States, state universities may have low tuition fees only for state residents. Also, welfare benefits often vary from one political unit to another within the same country. A second repercussion is that the migrant, unlike the mover, has changed his political unit. If he votes, his move has changed the electoral composition of two political units—his place of origin and his new location. Political Migration. There are two major motives for migration. Migration may be a response to differential economic opportunities or it may be a response to coercion or the threat of coercion. The former is generally called economic migration and the latter political migration. Economic migration is characteristic of modern and modernizing societies and generally reflects increased social mobility. It generally involves the voluntary, individual movement of young adults seeking better employment and higher wages. Political migration can occur in either premodern or modern societies, involving as it does an increased danger, or threat of danger, to individuals or groups. Since 1947, for example, an estimated 16 to 17 million people crossed between India and Pakistan as political refugees, as a result of the partition of the subcontinent and the violence associated with it. In 1922 and 1923, as a result of an unsuccessful effort by the Greek Army to invade Turkey, some 1,200,000 Greeks from Anatolia fled to Greece. It has also been estimated that something like a million Turks were "repatriated" from. The difference in growth rate seems cuts both ways. less important.